[tex]\bf \begin{array}{ccccccccc}
&&x_1&&y_1&&x_2&&y_2\\
% (a,b)
&&(~ 5 &,& 10~)
% (c,d)
&&(~ 8 &,& 16~)
\end{array}
\\\\\\
% slope = m
slope = m\implies
\cfrac{\stackrel{rise}{ y_2- y_1}}{\stackrel{run}{ x_2- x_1}}\implies \cfrac{16-10}{8-5}\implies \cfrac{6}{3}\implies 2
\\\\\\
% point-slope intercept
\stackrel{\textit{point-slope form}}{y- y_1= m(x- x_1)}\implies y-10=2(x-5)\implies y-10=2x-10
\\\\\\
y-=2x-10+10\implies y=2x[/tex]